In most commonly studied languages, the subjects of all sentences are marked the same way. In some less commonly studied languages including Nepali, however, subjects of transitive verbs are treated as subjects, while subjects of intransitive verbs are marked the same way as objects of transitive verbs. These are called “ergative” languages. If we imagine that English were an ergative language, the following pair of sentences would be grammatical:
“She saw him.”
“Him slept.” (rather than “He slept”).